With reduction in size, higher performance, and higher output of a motor in recent years, a coil formed from a rectangular wire capable of achieving an effectively improved space factor in a slot, in particular, what is called a segment coil obtained by forming a rectangular wire substantially in a U shape, has increasingly been demanded as a coil forming a stator of a motor.
A stator including such segment coils is generally formed by arranging a plurality of segment coils as aligned in slots of the stator and thereafter joining end portions of adjacent segment coils through arc-welding.
For example, PTDs 1 and 2 below exemplify related techniques showing such a segment coil.